Rate of Sweat Test

As the temps start to rise, I start to think about getting all my athletes to do a sweat test to find out their rate of sweat.

First lets talk about its limitations. A rate of sweat test tests how much you sweat out, it does not tell you what types of things; electrolyte, sodium, etc that you are sweating out. That can only be done in a lab setting with certain equipment. I know there have been sweat patches that have come out on the market, but they aren’t terribly accurate either. Just because you sweat it out onto your skin, doesn’t mean that it reflects what’s actually in your blood levels.

To begin, I think about making sure I am well hydrated the day before and the night before. Pee and eat breakfast as usual, weigh yourself (naked) before your run. Come back and weigh yourself again after an hour of easy/moderate exercise/running. Towel off any sweat, try to absorb some water from your hair if you have longer hair, and re-weigh yourself after running; before drinking or eating or going to the bathroom.

You can use this calculator which does allow for drinking during running, but its easier if you don’t need to rehydrate while running, because you will need to know exactly how much you drank (or on the flip side how much you peed.)

Now what does this tell you? Let’s say you ran in 80 degree weather at 50% humidity and lost enough water weight to equal a liter of fluid. This tells you that around 80 degrees and 50% humidity you want to try to rehydrate with a little less than a liter an hour. Why less, because while exercising your body is busying doing lots of things so its unable to fully rehydrate, or refuel for that matter, back to 100%. Also the body can withstand a little dehydration and hyponatremia is also a factor if you try to guzzle back all the fluid you lost each hour.

What else is it good for? Well often in the summer you can get chronically dehydrated and not quite know it. If you run for an hour every day, you don’t really need to carry water or electrolyte with you, and if you’re a busy human you probably shower quickly and grab a bite to eat and something quick to drink before you’re off to day care drop off or a work meeting. If you know you sweat about a liter, now you can fill a water bottle to go and make sure that you rehydrate over the next few hours with that liter (in addition to how much water you need on a regular basis to function.)

What else is it good for? For long run and long race prep. If you are training for an ultra, you can now make sure that if you’re going to be out running for 3 hours you have at least 3 liters of water available to you. (Even if you aren’t going to drink it all) You can take it a step further in your training and start testing out different types of electrolyte hydration mixes to see what your body likes as well.

Its also good for dialing in specific needs during a race. Let’s say you travel from the east coast to Colorado. You can do the sweat rate test where you are and see if your sweat needs change. With that in mind you can help prepare your crew to know how much fluid you (may) need during your ultra. It can also help you trouble shoot problems mid race. For example in 2019 during WSER the temperature fluctuated a lot from the chilly start to the hot canyons, I had a rough idea of how much fluid per hour I was sweating, so I ran with a pack that had a bit more than what I needed from each aid station to aid station. That way I could have a reminder of how much I drank, and later on when I started feeling sick, I knew I was getting enough fluid, but that I was getting too much sodium (from licking a salted potato and gagging that told me, no more salt!) so I could switch from the Skratch I was drinking to water and my nausea subsided.

As you get into better shape, and adapt to the heat, or the weather cools off you can redo the sweat test as often as you like to make sure you’re on top of things…and to see trends! (Which are cool)

Just keep in mind its a general guide and not an absolute. Here’s some more reading about sweat rate testing and things to keep in mind.

I Did Something for the First time….

….in more than a year…

I ran an IN PERSON race!

This spring, as I signed up for my vaccines, I started to feel a little more optimistic about running, racing, and normal life again.

I’d had quite the winter of depression and stress, as so many of us have. It’s not unusual for me to have a touch of the winter blues, I get a little withdrawn, want to sleep a little more, don’t want to see people nearly as much…but this winter was one of the worst I can remember in decades.

As a gift to myself, for dragging my emotions out of their winter cocoon funk, I started scanning trail races close to home. There were a lot of looped courses and timed races that have popped up since Covid, they didn’t really appeal to me. A race or two within 4 hours drive time…hmm, not yet. Uwharrie, that’s about a 2 hour drive…ok….20 miles, I can do that with my limited training and can carry all my food…check….gravel trail, small race….I was sold on it. It seemed like a good way to slowly dip my toe back into racing.

I know It seems like someone who has been racing for decades should have no problem with nerves, but it never really gets easier for me. Heck, I spent my 20s training like crazy but never racing because my race anxiety was so bad I hated the few races I ran. Since then I’ve spent a lot of time adopting coping skills or I go with friends who can take my mind of off my internal anxious monologue. However, this time I would be driving there and back alone, so no distractions, I just had to dust off my old coping skills and get in the car and go. So I did, I almost turned back and went to bed, but I am glad I didn’t!

The race started after 9am, so I was able to sleep at home and drive there that morning. It was held in Uwharrie National Forest, but in a section I had never seen before. It began at Kings Mountain Point, coincides with a 10 mile run, and a 75, 50, and 25 mile gravel bike race. The course was open to traffic, so there was quite a bit of dust kicked up by passing vehicles, was about a mile or so on paved road, 17 or so miles on dusty rolling gravel keep roads and 2 miles up a Jeep obstacle course of sorts. It had just under 2,000 ft of elevation and rolled up and downhill for the first 6-7 miles and then had a 350 ft climb from mile 9-12ish and a 600 ft climb from mile 13-14.5 or so, so I knew that I needed to run a smart race in order to have any legs for the two climbs on the back half.

This was a last minute sign up, so I didn’t have any specific training, I had mostly been running roads, sometimes running trail, I had run a few 20 mile trail runs a few months ago just because running on the road was getting a little boring. This meant I had to rely on taking it easy and running comfortably on the flats and downhill, I have always been a good down hill runner, I have a quick cadence and from practice I can lean forward and trust I won’t fall so my effort drops a lot and I can recover my heart rate on the downhill even if I pick up speed.

For the first 8 miles I relied on this, I would pass a bunch of runners on the downhills, and they would catch me on the uphills. At around mile 8 we had a small out and back climb, and one of the guys I was leap-frogging taunted me to catch him on the downhill. I laughed and thought to myself, “its only mile 8, I am going to catch you anyway…but just in my own time.” I did pass him on the downhill and never saw him again until the finish.

Running my race, I was in 7th (overall) for most of the first half. By mile 10 I had picked two men running together, by 12 I passed a few other men on a 1 mile rolling downhill. I kept anticipating the 2+mile uphill, a little nervous that almost all of my running the past 6 months has been flat, flat, flat (short of a few trips out to visit my sister last November and December in Black Mountain). The Jeep road didn’t disappoint. I had actually never seen anything like this on the east coast, I have seen them out west. Steep boulder trails that are specifically built for taking your off road vehicles (very slowly) down in hopes that you don’t flip them. I imagine its almost as exhilarating driving them as it was dodging them. The two miles up it was a mix of hiking, jumping out of the way of ATV’s Hummers and dirt bikes.

Finally I got to the 4 mile rolling descent to the finish. When I help my coaching clients get prepared for a race, I often tell them to mentally break any race up into 3 parts. Look at the elevation map, see where your strengths are, plan for the sections that may challenge you, and don’t “race” until you hit the final third, or even quarter if its a really long race. So here I was, having taken my own coaching advice, right on target for my race to start. My average pace was 7:32, the average pace of the final 4 miles downhill was around 6:55. The race was on! I could feel the lactate in my legs, I stuck a shot block in between my cheek and teeth to suck on while I went on the hunt. I picked off the last guy a mile from the finish, and then ran scared because I knew from chatting with him before the race that he used to run for UNC and if it came down to a final sprint there’s no way that my 40 year old legs could out run his early 20 year old ones.

I grunted and grinned my way across the finish in a big 20 mile trail PR, 3rd place overall, First female, in 2:28! Phew!

It was fun to race something shorter, It was a good exercise in pushing myself harder than I would normally in an ultra. It was great to sleep in my own bed, race and be home in time for a burger and some yard work! It was also nice to reassure me that even though I am over 40 I still have lots of racing ahead!

I know many of you reading haven’t raced in a while; maybe some of you are dying to race again, others may still feel unsure or hesitant to get back out after such a long break. I can honestly say part of me was dreading it before, but I am so glad I got my vaccines and then dusted off my racing shoes and my mental skills and ran a race finally!